Method and machine for spinning rovings



June 3, 1958 w. FRENZEL METHOD AND MACHINE FOR SPINNING ROVINGS Filed Oct. 12, 1953 INVENTOR. @Luy- FRENZEI- United States Patent G F METHOD AND MACHINE FOR SPINNING ROVINGS Walter Frenzel, Dresden, Germany Application October 12, 1953, Serial No. 385,646

8 Claims. (Cl. 5736) This invention relates to a method and machine for spinning rovings.

When spinning yarn from librous material by applying the drawing process to cotton, worsted and bast fiber spinning it was the usual practice hitherto to employ after the preparatory work one or more rovingV or ily frames on which the roving was slightly twisted, so that it could be wound on a bobbin while remaining still in drawable condition when introduced into the next drawing frame. On moving into the creel this highly sensitive roving is, however, subject to faulty drafts with the L result that cross-sectional variations occur in the finished yarn, which are diilicult to avoid. Furthermore, in an ordinary ily frame production is upwardly limited by the maximum spindle speed depending upon the llyer, and the troublesome winding operation requires an intricate mechanical equipment which gets easily out of order. In a cotton ily frame the revolving ilyer is unsymmetrical, one leg thereof on which the rotatable presser is arranged being hollow and the other one solid. The dierential motion, the pair of cone drums for varying bobbin speed and the motion of the bobbin rail for producing a double cone cop form make the ily frame cumbersome and therefore expensive with respect to both prime cost and operation. Measurements of power requirement disclose an extraordinarily low efficiency, since only about 13 percent of operating power was found to be used for spinning and the remaining 87 percent for keeping the machinery going.

The twisting of the roving interferes with spinning on the next fly frame in so far as between front and back rollers not only preliminary drafting has to take place but also untwisting to a certain extent to insure proper subsequent drafting. The twist of the roving exerts also some influence upon the reach between the drawing rollers and the division of the total draft into partial drafts of the drawing frame. Such a ily frame requires therefore careful adjustment and supervision of its parts as well as special attendance. There are numerous sources of trouble to be found in a ily frame of this type, which endanger the production of good readily drawable roving uniform as to twist and cross section.

It is the object of the invention to eliminate the abovementioned drawbacks of ily frames by simplifying their construction and at the same time considerably increasing their output. This object is attained by giving the roving having been drafted on a ily frame a hard twist which renders it undrawable, winding it on a bobbin, preferably of the double-flanged type, and then, for further treatment on a spinning machine, untwisting the roving directly before it enters the feed rollers of the drawing frame by means of a thread gripper revolving in a direction opposite to that of the twist until the roving becomes drawable again. The twist may be removed completely or in some cases just sufficiently enough to hold the roving together during drawing. When hornlike and not particularly pliable fibers, as bast, wool, synthetic ibers, and the like, are handled, it may be ad- 2,836,955 Patented June 3, 1958 visable after complete untwisting to add a few turns in the opposite direction to straighten such libers out. While in this fully controllable condition and immediately after having been untwisted in front of the feed rollers of the drawing frame of the next passage or spinning machine the roving is drawn in by them. If the twisting and untwisting members are driven by worm wheels the roving or intermediate yarn will receive a perfectly uniform twist which may be completely taken out again in the same way.

Owing to its greater strength, this hard-twisted undrawableroving can be wound on ordinary double-hanged bobbins in cylindrically parallel layers without involving the risk of cross-sectional variations. Upon removal of the bobbin from the ily frame, the bobbin is reversed end for end through whereupon the bobbin is passed in the reversed position to the spinning machine to be untwisted again.

The spinning machine for carrying out the method according to the invention is fitted in front of the roving feeding means of the drawing frame with a thread brake or gripper comprising for instance a pair of plate springs driven in a direction opposite to that of the twist of the yarn and forming a passage for the roving, and with a yarn guiding arm encircling the winding bobbin at the same speed as the gripper. The roving conducted to the gripping point retains therefore its undrawability up to and into this gripping zone, untwisting occurring only on the very short free .section between the thread gripper and the gripping zone of the pair of feed rollers. In the machine according to the invention this section may be made shorter than the medium length of the yarn fiber to prevent faulty draft due to the pull exerted by the drawing frame. A thread gripper forming a tapering rotary cone may be operating only a few millimeters away from the gripping zone of the rollers.

Although the cost of a spinning frame according to the invention will be somewhat higher due to the provision of the simple untwisting means infront of the drawing frame, the fly frame, on the other hand, will not need any more an equipment which as at present raises its manufacturing cost, lowers the quality of the yarn and limits output. The ily frame may be replaced for example by a simple ilyer of known type or by a ring spinning member so as to considerably accelerate spindle speed and thus not only compensate loss in delivery due to the hard twist of the roving but to increase production up to about 50 percent in some instances. The omission of the bobbin driving means, the differential and conoidal gearings for the variable rail lift, and the presser device simplies the fly frame and reduces its cost.

The invention affords the further advantage of permitting additional drawing of any yarn produced on a ily or spinning frame by simply taking out the twist thereof prior to the transfer to the drawing frame.

One embodiment of the invention is illustrated in the accompanying drawing, wherein Figure 1 is a diagrammatic view of the rear part of a ily frame during winding of the roving;

Fig. 2, a View of the front part of a spinning machine when the roving is transferred to the drawing frame; and

Fig. 3 shows a modification.

In the ily frame shown in Fig. l the sliver 2 drawn by the frame l passes through the bore 3 of the flyer spindle 4 driven in the direction of the arrow by the worm wheel drive S to the stationary flanged bobbin 6 on which it is wound up in parallel layers. The flyer spindle 4 disposed n the bearing 4a imparts to the roving 2a formed of the sliver 2 sulllcient twist to render it undrawable. The bobbin 6 rests on the dead spindle 7 the lower portion of which may be provided with a bobbin drag 7a, s0 that the roving can be wound on the bobbin 6 without any risk of cross-sectional reductions of the yarn due to increased tensile stress. The construction of this part of the y frame is therefore simplified, rendered less expensive and requires not so-much power.

jThe spinning' machine, shown in Fig. 2,.for further` drawinglispro'vided with` a flyer member 4 arranged directly' in front of the pair of feed rollersV 821 of the drawingfr'ame Sfin the bearing 4a, and driven by a worm wli'eel drive 5'.V Upon removal of the bobbin 6 carrying thelroving 2a, placed from the spindle 7 of the fly frame shownin Fig. 1,'the bobbin 6 is reversed end for end through'180"A so that .its flange a takes the position previously occupied by its ange b and vice versa, whereupon the bobbin 6 is onsthe spindle 7 of the fly frame shown'in FigLfZ', so that the roving 221 moving from the bobbin 6 along the flyer 4 and through the bore 3 passes between the springy sides of the tapering thread gripper 9 secured'tothe top end of the iiyer spindle 4. Owing to the gripping of the roving 2a by the gripper 9 and owing to therotation of the iiyer spindle 4 and the gripper 9 secured thereto in opposite direction to the direction of rotation of the flyer spindle 4 of the fly frame shown in Fig. 1`, twistV is fully or almost so taken lout ofthe roving 2a, depending on the degree of twist received, along the short distance between the thread gripper 9 and the feed rollers 8`a, which distance isfshorter than the medium length ofthe yarn fiber. In this drawable condition the roving is then cautiouslyintroduced into the drawing frame for further treatment., Hence it follows that even coarser yarns, as finished weft yarns, may still be further drawn and spun into iineryarns by removing again their twist. Instead of the yer 4 a ring spinning member may be used.

In the modification shown in Fig. 3 the bobbin 6 ylies on a higher'plane than the drawing means of the frame (not shown). The thread guide 103 supporting the flyer 104 and the thread gripper 109 comprises two parts connected' by bevel gears 110. The drive 10S can be disconnected by a clutch 111. This arrangement permits better utilization of the machine space. i

Comparative experiments disclosed the further advantage of an improvement of the quality of theV finished thread. Breaking length values, for instance, were found to be more favorable and those for unevenness decreased due Vto the fact that the hard-twisted roving had not been subjected to any drawing and was drafted and spun in twistless condition. The number of thread breakages was extraordinarily low..

I claim: Y

1. A methodrf'or spinning slivers, comprising the steps of: drawing outa sliver on a fly frame so as to form a v roving, subjecting said roving to a hard twist so as to render Vsame undrawable and winding simultaneously the 4 twisted roving on a bobbin, thereafter untwisting the roving for returning same into drawable condition by means of gripping means rotating in a direction opposite to the direction of the twist, and carrying out said untwisting shortly before the roving enters the feed rollers of the drawing frame of a spinning frame.

2. A method for spinning slivers as claimed in claim l, wherein said untwisting of the roving by said gripping means takes-place at aadistance from said feedA rollers shorter than the mediumlengtlrofthe yarn fibers of the roving. Y Y

3. A method for spinning slivers, as claimed in claim 1, whereinsaid roving isualmost entirely untwistedbysaid gripping means. f

4. A method for spinning slivers as claimed in claim 1, wherein said roving is completely untwisted by said gripping means. n

5. Infa method for. spinning sliversas claimedin claim l, the steps of completely untwisting the rovingandIadding a few turns-of twist in the opposite direction.

6. -`In a spinning machine having a drawing frameand. feeding means for feedinga roving thereto, a spindle.V arranged for receiving a bobbin on which twistedroving is wound andfrom which it is fed to the drawing frame,v a` flyer rotatable about said spindle and bobbin mountedv thereon and having means to guide the roving from the." bobbin to. the feeding means, rotatable gripping means for gripping said roving disposed directly before the feeding Y. means, andV driving meanscooperating with said flyer and. said roving gripping means to rotatey the same Fat equal speeds. n

7. In a spinning machine as claimed in claim. Y6, said rotatable gripping means being rigidly said flyer. p 8. In a spinning machine as in claim 6, said roving gripping means including a series of plate springs, said plate springs being formed in a tapering passage to guide,V

grip and untwist the roving. as it is fed from the bobbin to the feeding means.

Great Britain Sept. 8,

connected with. 

